Gutless attacker runs after coward punch

A sickening and unprovoked attack on an unsuspecting commuter waiting for a train has been captured on CCTV footage in Melbourne, sparking a police manhunt for the coward who fled the scene.

The incident took place about 8.45pm last Saturday at Richmond Railway Station's Platform 6.

A 30-year-old man was talking on his mobile phone when he was approached by another man, who appeared to be stumbling.

The video, shared by Victoria Police, shows the attacker approach the victim. It's not clear if words are exchanged, but the attacker walks past the victim then doubles back before delivering a hard punch with his left hand to the side of the victim's head.